There is a window. On that window, there is a crack. Flies that enter through the crack, become trapped inside the double glass.They spend their days trying to reach freedom through outter glass. In that quest they mostly die of hunger. All flies that die on second glass towards out, falling dead at the frame between two glasses. They remain trapped, even when they are dead. It rarely happens that fly dies on the inner glass, and then during its fall it comes to the crack through which it entered and finally passes through it, dead, into the freedom.